Control apparatus



Sept. 10, 1940. E. H. WHITE CONTROL APPARATUS Filed. March 11, 1938 2 Sma ts-Sheet 1 INVENTOR VE/FETT/l. WHITE BY ATTORNEY Se t. 10, 1940. s. H. WHITE 2,214,254-

CONTROL APPARATUS Filed larch ll, 1938 2 Sheets-Sheet 2 mmvroa A TTORNEY 30 animal or vegetable material to be preserved for Patented Sept. 10, 1940 UNITED STATES PATENT OFFICE,

9 Claims.

This invention relates to a control apparatus, and has more especial reference to an apparatus adapted to the purposes (l) 01' causing a gas, such, for example, as carbon dioxide, to be fed into an enclosed space to be there mixed with a different gas or gases, such, for example, as air, and (2) of controllably accomplishing or regulating the feed of said gas such as carbon dioxide into said enclosed space having said different gas or gases such as air in such manner as to, within limits, continuously maintain the concentration of the gaseous content, or atmosphere, comprised of both said gas and said different gas or gases, in said enclosed space at any desired and predetermined value.

It has heretofore been common practice to subject animal and vegetable materials, such as food stuifs and fiowers, which are to be preserved to atmosphere, usually kept at relatively low temperature, containing a quantity of carbon dioxide. As is well known, diflerent animal and-vegetable materials to be preserved for difierent periods of time are required to be constantly subjected to atmospheres including concentrations of carbon dioxide which are in certain instances diiferent from the concentrations in other instances it satisfactory preservation results are to be accomplished upon the materials. More specifically, in the instance of one or another animal or vegetable material to be preserved, or of a particular a longer or a shorter period of time, it is essential to the attainment of, or the approach toward, maximum preservation results that the material be subjected to an atmosphere concentrated with, or including, a quantity of carbon dioxide predetermined to be that quantity which is proper or most suitable for best accomplishing {preservation of said material over the period of ,4 The control apparatus of the present inventime it is intended to be stored for preservation.

tionmay be put to other uses, but it has been designed and illustrated to be, and will be described hereinafter as, more especially useful for the purposes 1) of originally establishing a concentration of atmosphere with carbon dioxide of any desired and predeterminedly selected value in an enclosed space adapted to receive animal and/or vegetable materials to be preserved; the concentration of atmosphere with carbon dioxide selected to be established in a particular instance of course to have value which is proper or most suitable for accomplishing the best preservation results upon the particular material or materials to be preserved; and (2) of thereafter continuously maintaining, substantially accurately and satisfactorily in actual practice, the concentration of atmosphere with carbon dioxide in said enclosed space at the desired and predeterminedly selected value at which originally established. 5 It is to be understood, however, that the control apparatus can be employed within the principles of the invention to establish and maintain any selected concentration of mixed gases other than air and carbon dioxide in an enclosed space, 10 whether said enclosed space is to be employed as a storage compartment for food stuffs or flowers to be preserved, or is to be employed for some other useful purpose.

An object of the invention is to provide a novel 16 and improved control apparatus which will be capable of causing a gas such as carbon dioxide to be fed into an enclosed space housing a different gas or gases such as air, of establishing a gaseous content, or atmosphere, comprised of said 20 gas and said different gas or gases, in'said enclosed space having any desired and predeterminedly selected concentration value, and of continuously maintaining, sufilciently accurately for all practical purposes, the concentration of said 25 gaseous content, or atmosphere, in the enclosed space at the value established by the control apparatus.

A further object is to provide a control apparatus for the general purposes as stated and wherein will be incorporated various improved features and characteristics of construction novel both as individual entities of the control apparatus and in combination with each other.

A further object is to provide a control apparatus of the nature as stated, adapted to cause a gas to be fed into an enclosed space housing a diflerent gas or gases and to establish and maintain a gaseous content, comprised of said gas and said different gas orgases, in said enclosed space having a desired and predeterminedly selected concentration value, which will include pressure actuated means capable'oi' operation to. cause flow of the first mentioned gas from a source of supply thereof into said enclosed space until the enclosed space contains a quantity of said first mentioned gas to constitute, together with said diflerent gas or gases, a gaseous content in said enclosed space having said desired and predeterminedly selected concentration value and to cause the supply of said first mentioned gas to the enclosed space to be shut off when said enclosed space contains a. gaseous content having said desired and predeterminedly selected concentration value.

A further object is to provide a control apparatus oi the nature as stated, adapted to cause a gas to be fed into an enclosed space housing a difierent gas or gases and to establish and maintain a gaseous content, comprised 0! said gas and said diflerent gas or gases, in said enclosed space having a desired and predeterminedly selected concentrationvalue, which will include a source of supply of said first mentioned gas under pressure, and means adapted tobe actuated by pressure oi gas from said source and capable of operation to cause fiow oi the first mentioned gas from said source into said enclosed space until the enclosed space contains a quantity of said first mentioned gas to constitute, together with said diflerent gasor gases, a gaseous content in said enclosed space having said desired and predeterminedly selected concentration value and to cause the supply of said first mentioned gas to the enclosed space to be shut oil when said enclosed space contains a gaseous content having said desired and predeterminedly selected concentration value.

A further object is to provide a control apparatus oi the nature as stated, adapted to cause a gas to be fed into an enclosed space housing a second gas or gases having physical properties different from the physical properties of said first mentioned gas and to establish and maintain a gaseous content, comprised of said gas and said second gas or gases, in said enclosed space having a desired and predeterminedly selected concentration value, which will include mechanism capable oi operation to cause flow oi the first mentioned gas from a source 01' supply thereof into said enclosed space until the enclosed space contains a quantity of said first mentioned gas to constitute, together with said second gas or gases. a gaseous content in said enclosed space having said desired and predeterminedly selected concentration value, and an entity adapted to be controllably moved to a plurality of different positions in response to alterations or fluctuations of the physical properties of the gaseous content in said enclosed space due to or caused by the presence of larger or smaller quantities of said first mentioned gas in said enclosed space and to render said mechanism incapable of operation to cause flow of the first mentioned gas into said enclosed space when the gaseous content in the enclosed space possesses said mentioned desired and predeterminedly selected concentration value.

A further object is to provide a control apparatus of the nature as stated, adapted to cause a gas to be iedinto an enclosed space housing a second gas or gases having physical properties diflerent from-the physical properties or said first mentioned gas and to establish and maintain a gaseous content, comprised of said gas and 'said second gas or gases, in said enclosed space having any desired and predeterminedly selected concentration value, which will include mechanism capable of operation intermittently or periodically to cause fiow ot-said first mentioned gas from a source or supply thereof into the enclosed space when the gaseous content in said enclosed space has concentration value different from said desired and predeterminedly selected concentration value to be established and maintained in the enclosed space, and an entity adapted to be actuated to each of a plurality of diilerent positions in response to alterations or fluctuations of the physical properties of the gaseous content in said enclosed space due to or caused by the pres- -tioned gas each in amount diflerent from desired and predeterminedly se'lected concentration value, and to render said mechanism in- I capable of operation to cause fiow oi the first mentioned gas into said enclosed space when the entity is situated at the position it assumes when the gaseous content in the enclosed space possaid mentioned desired and predeterminedly selected concentration'value.

With the above objects in view,- as well as others which will appear as the specification proceeds, the invention comprises the construction, arrangement and combination of parts as now to be fully described and as hereinafter to be specifically claimed, it being understood that the disclosure herein is merely illustrative and intended in no way in a limiting sense, changes in details of construction and arrangement of parts being permissible so long as within the spirit of the invention and the scope of the claims which follow.

In the accompanying drawings forming a part of this specification,

Fig, 1 is a diagrammatic view of a control apparatus made according to the invention;

Fig. 2 is an enlarged plan'view of a regulating means or the control apparatus of Fig. 1;

Fig. 3 is a view, partially in side elevation and partially in vertical section, of the regulating means of Fig. 2;

Fig. 4 is a detail sectional view, taken on line 4-4 in Fig. 3;

Fig; 5 is an enlarged elevational view, partially in section, of one type of cell which the control apparatus employs; and

Fig. 6 is an enlarged elevational view, partially in section, of a different type of cell which said control apparatus employs.

With respect to the drawings and the numerals of reference thereon, a structure i0 is adapted to the purpose or providing an enclosed space H which in the embodiment of the invention as disclosed is intended to be used as a. storage compartment or chamber for animal and/or vegetable materials, such-as food stuffs and flowers, to be preserved. A tank or vessel I2 is adapted to contain solid carbon dioxide, commonly called dry ice. A pipe connection, denoted generally at i3, leads from the tank or vessel l2 and is adapted to communicate with the interior of said enclosed space H through outlets l4 from said pipe connection. As shown, the pipe connection I! includes a usual reducing valve l5 therein.

The control apparatus of the invention is -or proper amount, are better preservatives for animal and/or vegetable materials to be preserved than are atmospheres not so permeated.

In addition to causing gaseous carbon dioxide to enter the enclosed space II, it is a function of the improved control apparatus to controliably accomplish or regulate the feed of gaseous carbon dioxide into said enclosed space. In short, the present apparatus has been designed to cause flow of carbon dioxide into the enclosed space H until this contains a quantity of carbon dioxide which will comprise, together with atmosphere, a gaseous content in said enclosed space having any desired concentration value which may before have been selected as proper or most suitable in a particular instance to best accomplish preservation of animal and/or vegetable material which is to be stored in the enclosed space for preservation, and to thereafter substantially accurately maintain said gaseous content at said desired and previously selected concentration value.

A regulating means of the control apparatus includes a mechanism, denoted generally at I6, for controlling flow of gaseous carbon dioxide from said tank or vessel 2 through said pipe connection |3 into the enclosed space H, and an entity i1 adapted to be actuated to a plurality of different positions in response to alterations or fluctuations of the physical properties of the gaseous content in the enclosed space H.

The mechanism l6 includes as a part thereof a ball valve l8 for controlling a port l9 between passageways 2|l constituted as portions of the pipe connection l3 and situated in a cage 2| of said mechanism i6. A coil spring 22 is for resiliently urging the ball valve l8 to closed position of the port I9. Said ball valve I8 is at the side of said port l9 which is adjacent the tank or vessel l2, and when the ball valve is seated, flow of carbon dioxide from said tank or vessel to the enclosed space H is precluded. When said ball valve is moved oil of its seat, however, in a manner to be set forth, there will be flow of carbon dioxide through the pipe connection I3 and the passageways 20, under pressure created at the tank or vessel l2, into the enclosed space H. Said mechanism l6 also includes as a part thereof a vertical plunger 23 slidably mounted, as at 24, in the cage 2|.- The lower end of the plunger 23 is in engagement with a surface of the ball valve l8 directly opposite the coil spring 22. Said plunger 23 extends upwardly a considerable distance above said cage 2|, and an intermediate portion of the plunger includes a collar 25 adapted for engagerhent with the cage 2| to limit the extent of downward movement of said plunger.

The entity I1 is in the disclosure as made adapted to be actuated to each of a plurality of diflerent positions in response to difierence in thermal conductivity of atmospheric air and gaseous content in the enclosed space H as said gaseous content becomes, or may become, altered because of the presence as a part thereof of larger or smaller quantities or portions of carbon dioxide. More specifically, the entity I1 is constituted as the needle of an ordinary microammeter 26. As shown, the microammeter 26 is mounted upon an upper cross member 21 of a frame 28 of the control apparatus, which frame suitably supports the cage 2|, and said entity or needle I! is desirably disposed to-have movement in a horizontal plane. The positions which the entity or needle i1 is capable of assuming include a position for said entity or needle corresponding to a quantity of carbon dioxide in the opposite the lead wire enclosed space which comprises, together with the atmosphere, a gaseous content in said enclosed space having the desired and predeterminedly selected concentration value to be established and maintained and positions for the entity or needle corresponding to variable quantities of carbon dioxide in the enclosed space each less than the quantity of carbon dioxide comprised as a portion of said gaseous content having said desired and predeterminedly selected concentration value.

The microammeter 26 is electrically connected into a Wheatstone bridge arrangement, indicated generally at 29. In the disclosure as made, said Wheatstone bridge arrangement includes a fixed resistance 30 and an adjustable resistance 3| having value in its entirety exactly equal to the value of said flxed resistance 36. A lead wire 32 connects an end of the fixed resistance 36 to an end of the adjustable resistance 3 I. The opposite end of said fixed resistance 3|) is connected by a lead wire 33 to an end of a resistance wire 34 housed in and stretched across a cylindrical closed cell 35, and the opposite end of said adjustable resistance 3| is connected by a lead wire 36 to an end of a resistance wire 31 housed in and stretched across a cylindrical perforate cell 36. The ends of the resistance wires 34 and 31, respectively, opposite the lead wires 33 and 36 are connected by a lead wire 33, common to both of said resistance wires 34 and 31, to one side of a battery 40. A lead wire 4| extends from the other side of said battery 40 and is commonly connected to an end of each of resistance wires 42 and 43, The resistance wire 42 is of the same structure as is the resistance wire 34 and is similarly housed in a cylindrical cell 44 of the same construction as the cell 35, and the resistance wire 43 is of the same structure as is the resistance wire 31 and is similarly housed in a cylindrical cell 45 of the same construction as the cell 38. A lead wire 46 commonly connects the ends oi the resistance wires 42 and 43 which are 4| to one terminal 41 for the microammeter 26, and a lead wire 48 extends between the other terminal 49 for said microammeter and a movable switch arm 56 in engagement with, and adapted to the purpose of adjusting the value of, the adjustable resistance 3|.

The construction of each of the duplicate cylindrical closed cells and 44 is best understood from Fig. 6, where the closed cell 35 is disclosed in detail. The resistance wire 34 is suitably stretched centrally through the length of the cell and is at one of its ends insulated from and made rigid with said cell, as at 5|. Said resistance wire 34 may be of nickel. At 52 the nickel resistance wire 34 is soldered to a coiled wire 53, which is for holding the nickel wire taut, and the coiled wire 53 is fixed, as at 54, in the end of said cell 35 opposite the insulation 5|. An expansion chamber 55 upon each closed cell and in communication with the interior of the cell is covered by'a flexible diaphragm 56 useful to the purpose of compensating for variations in operating results which might occur due to changes in barometric pressure were the arrangement as illustrated and described not employed.

The construction of each of the duplicate cylindrical perforate cells 38 and 45 is best understood from Fig. 5, where the perforate cell 38 is disclosed in detail. The resistance wire 31 is suitably stretched centrally through the length of 4 the cell and is at one of its ends insulated from and made rigid with said cell, as at 1. Said resistance wire 31 may also be of nickel. At II the nickel resistance wire I1 is soldered to .a coiled wire I, which holds the nickel wire taut, and the coiled wire N is fixed. as at l, in the end of the cell ll opposite the insulation 51. The enclosing or side wall of each perforate cell ll and l as shown composed of screening of comparatively fine mesh.

Each of the resistance wires 84 and I1 is desirably supported as at H! to eliminate possible vibration of the wire.

It is essential to the operation of the control.

apparatus that the perforate cells 38 and be situated within the enclosed space I l. The closed cells 35 and 44 are ordinarily adapted to contain atmospheric air. Said cells 35 and 44 may be situated either within or without said enclosed space H.

A scale ii for the movable switch arm is so positioned with respect to the adjustable resistance 3| that when a pointer l2 secured to said movable switch arm denotes zero on said scale ii the switch arm is, or may under certain conditions be, engaged with the end 83 of said adjustable resistance which is attached to the lead ,wire 32. It will be apparent, assuming the enclosed space H to contain only atmosphere so that the resistance wires ll, 31 and 42, 43 are all subject to the same condition, that when the movable switch arm II is engaged with the end 63 of the adjustable resistance II, the Wheatstone bridge will be balanced for the reason that the resistances ll and II are of equal value, and the entity or needle I! of the microammeter 26 will be, or have tendency toward being, at zero point it upon the scale O5 01 said microammeter. However, and still assuming that the enclosed space contains only atmosphere, when the movable switch arm 50 is moved toward the right in Fig. 1, to cause the adjustable resistance ii to have value less than the value of the fixed resistance 30, said entity or needle I! will move to a position away from and higher than its zero position, the extent of the movement of said entity or needle being directly proportional to the extent to which said movable switch arm is moved along said adiustable resistance 3 I In the disclosure as made, the entity or needle I! is prevented by a stop 86 from reaching its zero position in microamperes, said stop being arranged not far distant from said zero position. The stop 86 could, however, be arranged at the zero point it.

The mechanism 18 and are so related to each other that when said entity or needle is in position against the stop 86 it is situated to render said mechanism incapable of operation to move the ball valve I! of! of its seat, and when the entity or needle is otherwise situated, the mechanism I is capable of operation to move said ball valve It to open position against the resilient action of the coil spring 12. Stated otherwise, the mechanism I. is adapted to move the ball valve I! of! of its seat, intermittently or periodically in the disclosure as made, to cause carbon dioxide to flow into the enclosed space I I and when this is made to contain a quantity of carbon dioxide which comprises, together with the atmosphere, a gaseous content having a desired concentration value, it is the function of the entity or needle ll to cause said mechanism ii to be inoperative to move said ball valve l8 away from its seat. At times when the enclosed space H contains variable quantities oi carbon the entity or needle I'I the entity or needle I1 is spaced from thestop l to denote a measurement on the scale whichhas direct relation to the amount of carbon dioxide in the enclosed space H, said denoted measurement being'inversely proportional to the carbon dioxide content of said enclosed space. That is, when the carbon dioxide content in the enclosed space is'smaller, the denoted measurement on the scale is greater, and vice versa. When the enclosed space is made to includethe quantity of carbon dioxide for which the control apparatus is set, the entity or needle I! is against the stop 68, at which position it will funcmade to reach its position tion to render the mechanism IO inoperative to open the valve l8.

The extent to which the movable switch arm 50 is adjustably moved along the adjustable resistance 3| in direction away from the end 83 thereof predetermines .the quantity of carbon dioxide whichis to be maintained in the enclosed space H, the quantity. to be proportionately larger with greater adjustment and proportionately smaller with less adjustment of said movable switch arm. The exact amount of carbon dioxide it is desired that the enclosed space shall contain can be predeterminedly selected by reference of the pointer 62 to the scale 6|. As before mentioned, when the switch arm 50 is moved toward the right in Fig. 1, the Wheatstone bridge 29 is unbalanced, and the entity or needle I1 is moved toward a higher value on the scale 85. When the mechanism l6 opens the valve H to cause carbon dioxide to be fed into the enclosed space, the entity or needle I! will be caused to move gradually back toward its zero position, for the well known and obvious reason that the resistance of the resistance wires 31 and 43, subjected to the gaseous content of the enclosed space, will become proportionately greater as the quantity of carbon dioxide in said nism i6 is suitably and conveniently supported upon a fitting 88 itself carried by a lower cross member 69 of the frame 28. A pipe connection 10 leads from a portion of the pipe connection l3 between the tank or vessel l2 and the ball valve i8 and connects with the fitting 68 to communicate with a vertical channel ll through said fitting and opening to theinterior of the bellows 81. The channel H includes a restriction 12. The pipe connection 10 could just as well lead from the tank or vessel l2 to the fitting 68 independently of the pipe connection l3, and, in fact, said pipe connection 10 could lead to said fitting 88 from a source of supply of air or other gas under pressure other than the source of supply which the solid carbon dioxide in the tank or vessel l2 constitutes. Gas under pressure, carbon dioxide from the tank or vessel 12 as disclosed, is adapted to travel through the pipe connection Hi and the channel H, past the restriction 12 in said channel Ii, and into the bellows 81.

longer, upper arm 81 and the ball valve Vertical members 13 at one side of the frame 28 pivotally support, as at 14, a substantially horizontally inwardlyextending lever 15. An intermediate portion of said lever 15 engages a boss 16 upon the upper wall or surface of the bellows 61, and coil springs 11, one being shown, are for urging the lever 15 downwardly against the boss 16 to thus cause the bellows 61 to have tendency toward being shortened against the action of gas under pressure adapted to at times cause said bellows to be lengthened. Each coil spring 11 has its upper end engaged with a pin 18 upon the free end portion of the lever 15 and its lower end secured to the frame 28 as at 19.

A pipe connection 88 leads from a portion of the channel 1| between the restriction 12 and the bellows 61 to a channel 8| in a second fitting 82 suitably supported upon the frame 28. The channel 8| leads to an outlet 83 from the fitting 82 through a port 84 of less diameter than said channel 8| but of considerably greater diameter than the restriction 12. The channel 8| receives gas under pressure from the channel H. The outlet 83 is constituted as a part-spherical, vertically disposed valve seat, and a ball valve 85 is adapted to be brought at times into engagement with said valve seat to preclude the escape of gas under pressure from the channel 8| and to become removed at times from the valve seat to permit the escape of gas from said outlet 83 at rate of fiow faster than the gas, carbon dioxide as illustrated, will flow through the restriction 12 from its source of supply.

Devices for causing the ball valve 85 to become engaged with its seat to close the outlet 83 and hold it closed, and for permitting said ball valve 85 to become removed from its seat by reason of pressure of gas in the channel 8|, include an L-shape lever 86. A longer. upper arm 81 of the lever 86 is upstanding and a shorter, lower arm, or arms, 88 of said lever 86 has its intermediate portion pivoted, as at 89, upon the fitting 82. One or more coil springs 88, one being shown, have their upper ends engaged with the pin or pins 18 and their lower ends engaged with a pin or pins 8| upon the arm or arms 88 and located at the side of the pivot 88 opposite the longer, upper arm 81. The coil springs 88 have potential, which is increased as the bellows 61 is elongated and the lever 15 is thus elevated, to move or swing the longer, upper arm 81 of the lever 86in direction away from the fitting 82 and the closing position of the ball valve 85. A permanent magnet 82, fixed as at 83 upon the upper surface of the fitting 82, is adapted to the purpose of causing the longer, upper arm 81 of the lever 86 to be moved toward and held in closing position of the ball valve 85. To this end, said longer, upper arm 81 rigidly carries a suitable armature 94 for said magnet, said armature 94 being situated substantially in the plane of said magnet, which plane is horizontal as disclosed.

The longer, upper arm 81' of the lever 88 does not itself directly cause the ball valve 85 to become seated and to remain in seated, .closed position of the outlet 83. Instead, a leaf spring or resilient member 85, disposed between the 85, in the vertical and horizontal plane of said ball valve, has its lower portion secured, as at 96, to the longer, upper arm 81 and its upper portion disposed in substantially parallel, slightly spaced relation to said longer, upper arm.

The devices for controlling the ball valve 85 additionally include an actuator element 81 rigid 5 upon the longer, upper arm 81 of the lever 88, directly opposite the armature 94 as sho adapted to be engaged by the beveled or oblique outer end or surface 88 of the lever 15 when this lever is caused to be moved downwardly by the coil spring or springs 11, In a manner to be made plain, and thus actuated In direction toward said ball valve.

Said devices for controlling the ball valve 85,

also include elements for positively moving or swinging the longer, upper arm 81 of the lever 86 in direction away from the ball valve 85 and thus causing the armature 84 to be released from the magnet 92 when the bellows 61 is caused to become elongated by reason of pressure of gas therein. Of said mentioned elements, numeral 99 denotes a lever, which is independent of the lever 15, disposed directly above said lever 15 in vertical alinement therewith and having one of its ends mounted upon the pivot 14. The lever 88 is longer than the lever 15, and the free end portion of said lever 98 is disposed directly below an upright or vertical'actuator post I88. The post I88 is mounted in the cross member 21 of the frame 28 to be freely slidable therein, and the lower end of said post I88 rests upon the upper surface of said lever 88. A vertical member I8I of said frame 28 pivotally supports, as at I82, an L-shape lever I83 including a substantially horizontal arm I84 and a substantially vertical arm I85. The pivotal support I82 for said lever I83 is as disclosed at the juncture between said arms I84 and I85. A reduced extension upon the upper end of the actuator post I88 freely enters an opening I86 in the horizontal arm I84 and provides a shoulder I81 upon said post engaged beneath said arm I84. A lower portion I88 of the vertical arm I85 of the lever I88 is disposed in horizontal alinement with an upper extension. I88 of the longer, upper arm 81 of the lever 86, above the armature 94, at the side of saitdagxtension I89 and arm 81 adjacent the magne Certain of the elements as already described additionally function in cooperation with other elements of the control apparatus to the purposes of causing the ball valve I8 to be intermita particular setting of said conintends, and of rendering the incapable of moving said ball valve I8 oil of its seat when the entity or needle I 1 is at its position of engagement with the stop 66. To the accomplishment of these last mentioned purposes, the horizontal arm I84 of the lever I83 has a finger I I8 upon its free end. Said finger 8 extends downwardly from said arm I84 and is situated directly above an opening II I in the microammeter 26, said opening III ,being located adjacent the stop 68 to be directly below the entity or needle I1 when this is engaged with said stop. The arrangement is suchthat the finger H8, at times as to be set forth, may enter the opening III when the entity or needle I1 is at any of its positions except its position against the stop 66 in covering relation to said opemng III, but is precluded from entering the opening III by said entity or needle when this covers said opening. The horizontal arm I84 of the lever I83 has suflicient weight to overbalance the vertical arm I85 01' said lever, and said vertical arm as p portion which is adapted during the operation of the control apparatus to be positioned at times beneath the outer end portion of the lever 88, as disclosed in Fig. 3, and to be positioned at times clear of said lever 88, as disclosed in Fig. 1. An outer portion of the lever 88 is directly above the upper end of the plunger 28 in vertical aiinement therewith, and said plunger 28 is adapted to be engaged by said lever 88 under pressure exerted by a coil spring H8 situated between the cross member 21 and the lever 88 to be thus urged downwardly to move the ball valve l8 oil of its seat against the action of the coil spring 22 at certain times during the operationof the control apparatus when the hook or ledge H2 is clear of said lever 88.

Suppose, for the sake of convenience of explanation, that the control apparatus is placed in operation when the bellows 411 is shortened or depressed and the ball valve 85 is in. seated position. Immediately, gas pressure begins to be built up within said bellows 81, at the rateof course which the restriction 12 permits, and the bellows commences to lengthen or expand against the resilient action of the coil spring or springs 11. Lengthening or expansion of said bellows 61 causes the lever 15 to be moved or swung upwardly, and upward movement of said lever 15 increases the potential of the coil springs 88 which have tendency toward moving or swinging the longer, upper arm 81 of the lever 85 away from the ball valve 85. The attraction of the magnet 82 for the armature 84 is of sufiicient magnitude to preclude the coil springs 88 when acting alone, even under their greatest tension, from removing said armature 84 from engaged relation with said magnet 82, and, obviously, as long as the ball valve 85 engages its seat, the bellows 81 will continue to elongate or expand, of course assuming a pressure in the pipe connection 18 suflicient to elongate or expand the bellows, at first against the combined resilient action of the coil springs 11 and 88, and later against the combined resilient action of the just mentioned coil springs and the coil spring H3. Eventually, and while the armature 84 is engaged with the magnet 82, the bellows 81 is elongated or expanded by the gas pressure to an extent causing the lever 15 to push the lever 88 upwardly and cause it to elevate the vertical actuator post I00, with force applied by reason of pressure of gas in the bellows 81. Elevation of said actuator post, which has its shoulder I81 engaged with the horizontal arm I84 of the lever I83, causes said horizontal arm to be moved or swung upwardly and the vertical arm N5 of said lever I88 to as a result be moved or swung in direction toward the extension I88 uponthe longer, upper arm 81 of the lever 85, inwardly as disclosed. The arrangement is such that the lower portion I88 of the arm I85 will engage said extension I08 and cause the longer, upper arm 81 of the lever 86 to be moved a slight distance away from the ball valve 85 and the fitting 82 and the armature 84 to be forcibly separatedv from the magnet 82. The just mentioned movement of said arm 81 by the arm I85 under pressure of gas in the expanding bellows 81 will not, however, cause the ball valve 85 to be unseated, for the reasonthat the leaf spring 85 is flexed toward the ,arm 81 when the magnet 82 is retaining the armature 84, and during the positive separating movement of said armature 84 from said magnet 82 by said arm I85 said leaf spring 85 is urged outwardly from the arm 81 because of its natural resilience to maintain said ball valve 85 against its seat, as will be understood. The

pull of the magnet 82 upon the armature 84 varies of course, as does the pull of any magnet, in-

said magnet unable to retain said armature.

against the action of the coil springs 88, which coil springs are at the time the armature is positively separated from the magnet in the manner as stated under considerable potential or tension because of the fact that the lever 15 is elevated. Said lever 15 is in fact at or adjacent to the highest position it can assume when the arm I05 causes the armature 84 to be positively released from the magnet 82, because immediately upon positive separation of said armature from said magnet, the coil springs 88 act to move or swing the arm 81 of the lever 85 in direction further away from the ball valve 85 and the fitting 82 and to cause the leaf spring 85 to be released or relieved from said ball valve 85 with a snap action.

Immediately upon release or relief of the ball valve 85 from its seat, said ball valve is caused by pressure of gas to become removed from its seat, as in Fig. 3, and the arrangement is such that opening of the outlet 83 causes pressure of gas in the bellows 81 to become greatly reduced. More specifically, when the ball valve 85 is of! of its seat, gas is permitted to escape from the outlet 88 faster than it can build up in the channel 1| and the interior of the bellows 81 by passage from the source of supply through the restriction 12, because, as before stated, the pipe connection 88, the channel 8! and the port 84 have capacity for flow of the gas at rate considerably greater than the rate at which the gas can flow from its source through the restriction 12. In practice, movement of the ball valve 85 to open position causes the pressure of gas in the bellows 81 to be reduced to an extent which will permit the coil springs, 11, 88 and III at first, and 11 and possibly finally, to more or less gradually shorten or depress said bellows 51 by forcing the levers 15 and -88 downwardly. As said lever 15 is moved downwardly, its beveled or oblique end or surface 88 is brought into contact with the actuator element 81, and, through the instrumentality of said actuator element 81 the longer, upper arm 81 of the lever 88 is moved toward the ball valve and the fitting 82. The arrangement is such that engagement of the beveled or oblique surface '88 with the actuator element 81 does not cause the leaf spring 85 to have movement actually seating the ball valve 85. Rather, it is necessary that said ball valve be closed with a snap action, as well as opened with a snap action, so that the bellows 81 cannot possibly become balanced. To this end, the beveled or oblique surface 88 causes the longer, upper arm 81 of the lever 88 to be moved or swung a distance to position the leaf spring 85 at location just short of seating said ball valve, and, when said arm 81 so positions said leaf spring, the magnet 82, now operating against considerably reduced potential or tension possessed by the coil springs 88 due to the lowered position of the lever 15,. quickly attracts the armature 84 and thus causes the arm 81 to be moved toward the fitting 92 with a jerk and the leaf spring 95 to seat the ball valve 85 with the desired snap action. As soon as the ball valve 65 becomes seated, pressure again begins to be built up in the bellows 61 and the operations as described are repeated. In practical operation of the control apparatus, the operation of the mechanism I6 as thus far described will be continuously repeated regardless of whether the ball valve I8 is seated as in Fig. 3 or is unseated as in Fig. l.

Suppose now that operations of said mechanism I6 as before described are being carried out or repeated while the space II contains no carbon dioxide, or contains a quantity of carbon dioxide less than the quantity for which the movable switch arm is set. In such event, the entity or needle I! will be at one of its positions other than its position against the stop 66 and over the opening III. convenience of explanation, that the bellows 61 is shortened or depressed, that the ball valve 85 is seated, that the finger H0 is situated in the opening III so that the hook or ledge H2 is removed from the lever 99, and that the ball valve I8 is unseated due to the fact that the lever 99 is bearing down against the vertical plunger 23 so that the collar 25 on said plunger is engaged with the cage 2|, as the parts of the control apparatus are disclosed in Fig. 1. Pressure builds up in said bellows 61 in the manner as already stated to accomplish the operations of the mechanism I6 as hereinbefore set forth. Upon upward movement of the lever 99, to posi tion just below the position where said lever 99 engages the vertical actuator post I00, the ball valve I8 is released to the closing action of the coil spring 22. Stated differently, as the lever 99 is elevated it is gradually removed from the vertical plunger 23 to permit the ball valve I8 to be moved to its seat by the coil spring 22. Upward movement of said lever 99 which causes the actuator post I00 to elevate the horizontal arm I04 of the lever. I03 to thus cause the vertical arm I05 of said leverto separate the armature 94 from the magnet 92, as before set forth, also causes the finger IIO to be elevated and thus removed from the opening III. mencement of downward movement of the levers I5 and 99 as before set forth, which downward movement commences immediately upon the ball valve 85 becoming unseated, the horizontal arm I04 of the lever I03 becomes depressed by gravity so that the finger IIO enters the opening III and the vertical arm I05 of said lever I 03 becomes actuated, or overbalanced, to remove the hook or ledge II2 from position beneath said lever 99. Continued downward movement of the lever 99, under action of the coil spring II 3, forces the plunger 23 down to remove the ball valve I8 from its seat. Downward movement of said plunger 23 and said lever 99 is stopped by engagement of the collar 25 with the cage 2|. With seating of the ball valve 85, in the manner as before set forth, pressure again begins to be built up in the bellows 61 and all of the operations are repeated. Evidently, the ball valve I 8 is moved intermittently or periodically to open and closed positions during operation of the control apparatus to cause the intended quantity of carbon dioxide to be present in the enclosed space I I. When said enclosed space contains the requisite amount of carbon dioxide, the entity or needle I! is at its position against the stop 66 and over the opening II I, as already stated. When said Upon the com- Suppose also, for the sake of entity or needle I1 is in position covering said opening III and the levers I5 and 99 move downwardly, after having moved upwardly to elevate the entity or needle, downward movement of the finger H0 is precluded by said entity-or needle, and thus is the hook or ledge II2 maintained beneath the lever 99 to arrest downward movement of said lever 99 required to cause the ball valve I8 to be moved from its seat. Stated differently, when, the entity or needle arrests downward movement of the finger IIO, the hook or ledge II2 upon the vertical arm I05 of the lever I03 renders the mechanism I6, and more specifically the lever 99 thereof, incapable of actuating the ball valve I8. Once during each upward and downward movement, or reciprocation, of the bellows 61 the finger H0 .is lifted completely out of the opening III to spaced position above said opening. Thus said finger IIO can possibly offerno more than momentary and negligible or insignificant interference to engagement of the entity or needle I1 against the stop 66.

There will of course be escape of carbon dioxide from the enclosed space II after this has been made tohouse a gaseous content having carbon dioxide in intended quantity. As soon as the quantity of carbon dioxide is reduced to an extent causing the entity or needle to uncover the opening III, additional carbon dioxide will obviously be made to enter said enclosed space until said entity or needle assumes its position against the stop 66.

Desirably, the pointer 62 may be connected to the movable switch arm through the instrumentality of a bimetallic strip III the evident purpose of which is to constitute a thermostatic compensator which will cause said pointer 62 and switch arm 50 to adjust their relative positions with change of temperature. As shown. the movable switch arm 50 is situated within the enclosed space I I. Ordinarily, the carbon dioxide content of said enclosed space should be increased somewhat i'or higher temperatures and decreased somewhat for lower temperatures in the enclosed space. The bimetallic strip or thermostatic compensator I I4 is adapted to the purpose of moving the switch arm 50 relatively to the pointer 62 upon alteration of temperature in the enclosed space and so that said switch arm will adjust itself along the adjustable resistance 3| to a location which will cause a predetermined quantity of carbon dioxide to be included in the gaseous content of the enclosed space II selected to be proper for or most suitable to the temperature condition in said enclosed space, as well as proper for or most suitable to other conditions in the enclosed space required to be considered and hereinbefore briefly mentioned.

The control apparatus can incorporate a microammeter which is sensitive to variation in the proportion of carbon dioxide to atmosphere in an enclosed space in amount less than one half of one percent, and when properly constructed and installed can be depended upon to, and does in actual use, constantly maintain the intended proportion of carbon dioxide to atmosphere in an enclosed space within an amount less than one percent. In the disclosure as made, the entity or needle I! is quite stably mounted and balanced, and is not liable to be adversely affected to become unfit or inoperative for its intended or designed purpose even under the most trying or ex- I partment of a freight car or automotive vehicle subject to considerable jarring and bobbing in transportation. As will be evident, the mechanism I. is continuously operative to intermits'tently or periodically check the position of the entity or needle ll at all times while the control apparatus is in operation. The ball valve I8 is engaged with .its seat at intervals while the mechanism I6 is checking the position of the en- 10 tity or needle. It has been found satisfactory under certain conditions of use of the control apparatus to employ an arrangement which causes said mechanism II to accomplish a complete up and down movement, or reciprocation, in about one minute, more or less. The mechanism I0 is,

in its entirety, mechanical and requires no electrical power. The only electrical power which the control apparatus itself includes in the disclosure as made is that which the battery ll, or some equivalent source of electrical power, is employed to supply.

It is to be noted that upon either failureor lessening of the current supplied by the battery 40, or equivalent, the entity or needle II will be 2 located against, or have tendency toward being located against, the stop 68 and over the opening Hi to cause the hook or ledge H2 to be positioned beneath the lever 99 and thus render said lever 89 incapable of actuating the plunger 28 to 30 move the ball valve i8 oil! of its seat. That is,

upon failure of the supply of current to the electrical instrument 28, the mechanism 18 will be made incapable of actuating the ball valve i8 to allow flow of carbon dioxide into the enclosed space H, and upon lessening of the supply of current to said electrical instrument 26, said en-' tity or needle I! will be positioned over the opening III to preclude further flow of carbon dioxide into said enclosed space H when the enclosed 40 space includes aquantity or proportion of carbon dioxide not as great as the amount which said enclosed space included before the supply of current to the electrical instrument was lessened. Obviously, the construction and arrangement as illustrated and described makes provision for location of the entity or needle I! over the opening ill in response to failure of current at the electrical instrument 26, as well as in response to b'al ancing of the Wheatstone bridge, so that upon failure of current at said electrical instrument, the feedingof carbon dioxide into the enclosed space H past the ball valve ll will be prevented.

. What is claimed is:

l. A control apparatus for causing a gas to be fed into an enclosed space housing a second gas having physical properties different from the physical properties of said gas and for establishing and maintaining a gaseous content in said enclosed space consisting of said gas and said second gas and including a predetermined quantity of said gas, comprising a mechanism capable of operation to cause flow of said gas from a source of supply thereof into said enclosed space until the enclosed space contains said predetermined quantity of said gas, an. entity adapted to be actuated to a plurality of different positions in response to alteration of the physical properties of the gaseous content in said enclosed space as caused by the presence of variable quantities of said gas in the enclosed space, including a position for said entity corresponding to a gaseous content in said enclosed space containing said predetermined quantity of said gas, means under the control of said entity for rendering said mechanism incapable of operation to cause substantial flow of said gas into the enclosed space when the entity is situated at its position corresponding to a gaseous content in said enclosed space containing said mentioned predetermined quantity of said gas, and means operative in 5 response to differences in thermal conductivity of the gaseous content in the enclosed space resulting from alteration of the physical properties of said gaseous content to actuate and regulate the position of said entity. l0

2. A control apparatus for causing a gas to be fed into an enclosed space housing a second gas having physical properties different from the physical properties of said gas and for establishing and maintaining a gaseous content in said 16 enclosed space consisting'of said gas and said second gas and including a predetermined quantity of said gas, comprising a mechanism capable of operation to cause flow oi said gas from a source of supply thereof into said enclosed space until 20 the enclosed space contains said predetermined quantity of said gas, an electrical instrument including an entity thereof adapted to be actuated to a plurality of diflerent positions in response to alteration of the physical properties of the gas- 25 eous content in said enclosed space as caused by the presence of variable quantities of said gas in said enclosed space, including a position for said entity corresponding to a gaseous content in said enclosed space containing said predetermined quantity of said gas, means controlled by said entity adapted to render said mechanism incapable of operation to cause flow of said gas into the enclosed space when the entity is situated at its position corresponding to a gaseous con- 35 tent in said enclosed space containing said mentioned predetermined quantity of said gas, and means operative in response to diflerence in thermal conductivity of the gaseous content in the enclosed space resulting from alteration of 40 the physical properties of said gaseous content to actuate and regulate the position of said entity, said means including a fixed resistance, a resistance capable of adjustment in value, a resistance wire adapted to be subjected to the gaseous con- 45 tent in the enclosed space, a resistance wire adapted to be subjected to a gas other than the gaseous content in said enclosed space, and an electrical circuit including both of said resistances, both of said resistance wires and said in- 50 strument.

3. The combination as specified in claim 2, a switch element in engagement with and movable relatively to said resistance capable of adjustment in value, said switch element being con- 55 stituted as a thermostatic compensator included in said electrical circuit and situated in said enclosed space, and a support for said switch element,

4. A control apparatus for causing a gas to be 5 fed into an enclosed space housing a different gas and for establishing and maintaining a gaseous content in said enclosed space consisting of said gas and said different gas and including a predetermined quantity of said gas, comprising 5 a source of supply of said gas, a pipe connection from said source of supply to said enclosed space, valve means for controlling flow of said gas from its source of supply through said pipe connection into said enclosed space, and means for regulat- 10' ing said valve means to cause flow of said gas from said source of supply into said enclosed space until the enclosed space contains said predetermined quantity of said gas and to cause the supply of said gas to said enclosed space to be 15 discontinued when the enclosed space is made to contain said mentioned predetermined quantity of said gas, said means including a member such as a bellows adapted to be expanded by pressure, a resilient device for contracting said member, an outlet from said member, a valve for controlling said outlet to thus control pressure in said member, said valve being adapted to be moved to open position of the outlet upon expansion of said member to a predetermined extent to cause relief of pressure in said member and to thus render said resilient member capable of contracting said member and being adapted to be moved to closed position of the outlet upon contraction of the member to a predetermined extent to thus create pressure in said member and cause the member to be expanded, a mechanism responsive in its operation to movements of said member and capable of actuating said valve means to cause flow of said gas from said source of supply into said enclosed space until the enclosed space contains said predetermined quantity of said gas, and an element for rendering said mechanism incapable of actuating said valve means to cause flow of said gas from said source of supply into said enclosed space when the enclosed space is made to house said mentioned predetermined quantity of said gas.

5. The combination as specified in claim 4, a movable arm including a spring thereon for engaging said valve, an armature upon said arm, a permanent magnet for attracting said armature to cause said spring to maintain said valve in closed position of said outlet under flexed tension of said spring, said mechanism being adapted to actuate said movable arm in direction away from said valve to separate said armature from said magnet in response to expanding movement of said member and cause said spring to become unfiexed, and a resilient entity adapted to be under increased tension when said member is expanded and under decreased tension when said member is contracted for causing said spring to be withdrawn from said valve with a snap action when said armature is caused to be separated from said magnet by expanding movement of said member, said mechanism being adapted to actuate said movable arm with spring in direction toward said valve in response to contracting movement of said member, and said magnet being adapted to attract said armature in opposition to decreased tension of said resilient entity when said arm with spring is moved toward said valve to cause said spring to close said valve with a snap action.

6. A control apparatus for causing a gas to be fed into an enclosed space housing a second gas having physical properties difierent from the physical properties of said gas and for establishing and maintaining a gaseous content in said enclosed space consisting of said gas and said second gas and including a predetermined quantity of said gas, comprising a source of supply of said gas, a pipe connection from said source of supply to said enclosed space, valve means for controlling flow of said gas from its source of supply through said pipe connection into said enclosed space, and mechanism for regulating said valve means to cause flow of said gas from said source of supply into said enclosed space until the enclosed space contains said predetermined quantity of said gas, said mechanism ineluding a member such as a bellows adapted to be expanded by pressure, a resilient device for contracting said member, an outlet from said member, a valve for controlling said outlet to thus control pressure in said member, said valve being adapted to be moved to open position 01' the outlet upon expansion of said member to a.- predetermined extent to cause'relief of pressure in said member and to thus render said resilient member capable of contracting said member and being adapted to be moved to closed position of the outlet upon contractionof the member to a predetermined extent to thus create pressure in said member and cause the member to be ex panded, and an element responsive in its operation to movements of said member and capable of actuating said valve means to cause flow of said gas from said source of supply into said enclosed space until the enclosed space contains said predetermined quantity of said gas, and an entity responsive in its operation to alteration of the physical properties of the gaseous content in said enclosed space as caused by the presence of variable quantities of said gas in the enclosed space to cause the supply of said gas to said enclosed space to be discontinued and to render said mechanism incapable of actuating said valve means when the enclosed space is made to house said mentioned predetermined quantity of said gas.

7. A control apparatus comprising a mechanism capable of operation tocause flow of a gas from a source of supply thereof into an enclosed space housing a second gas having physical properties different from the physical properties of said gas, an entity adapted to assume different positions, means controlled by said entity when in a predetermined position for rendering said mechanism incapable of operation to cause flow of said gas into the enclosed space, and means including an electrical circuit adapted tohave its characteristics altered in response to difierences in the thermal conductivity of the gaseous content in said enclosed space as caused by the presence therein of varying quantities of said firstmentioned gas for controllably actuating said entity, said means being adapted to cause said entity to move toward said predetermined position upon the lessening of the amount of electrical energy in said circuit and to move to said predetermined position upon the failure of electrical energy in said circuit.

8. A control apparatus comprising a structure providing an enclosed space adapted to house a gaseous mixture consisting of a gas and a second gas having physical properties different from the physical properties of said gas, mechanism for causing flow of said gas from a source of supply thereof into said enclosed space there to be commingled with said second gas, devices for establishing and maintaining a gaseous content in said enclosed space consisting of said gas and said second gas, said devices including an electrical circuit dependent in its characteristics upon the thermal conductivity of the gaseous content of said enclosed space to cause a predetermined quantity of said gas to be maintained in said enclosed space, and means constituted as part of said devices for rendering said mechanism incapable of supplying substantial quantities of said gas to said enclosed space upon 'failure of said circuit.

9. A control apparatus comprising a structure providing an enclosed space adapted to house a gaseous mixture consisting of a gas and a second gas having physical properties different from the physical properties of said gas, mechanism for causing flow of said gas from a source of supply thereof into said enclosed space there to be commingled with said second gas, devices for estabsaid enclosed space consisting of said gas and said second gas, said devices including an electrical circuit dependent in its characteristics upon the thermal conductivity of the gaseous content of said enclosed space to cause a predetermined quantity of said gas to be maintained in said enclosed space, and means constituted as part lishing and maintaining a gaseous content in of said devices adapted to cause the quantity of said gas included as a portion of said gaseous content to be decreased with lessening of the amount of electrical current in said circuit and to render said mechanism incapable oi supplying substantial quantities of said gas to said enclosed space upon failure of said circuit.

EVERETT H. WHITE. 

